I think other sites advance to catch up with DD but still have lower standards like I'm a PA rookie and sleep is part of the rank team, this is their ranks compared to ours:
PA beginners= DD low beginners
PA rookies= DD med and high beginners
PA inters= DD borderline inters and low inters
PA advanced= DD medium and high inters along with borderline vets, vets and elites.
Sorry it's only compared to PA but it's the only other forum I'm on.
I've also noticed how allot of DD people are also on PA like strider neo and ECCO-SM.